Arc-lamp electrode.



omrnn STATES PATENT orrion.

CHARLES ESTEINMETZ, SCHENECTATJY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY CORPORATION OF NEW ARC-LAMP ELECTRODE.

To all whom it may concern p Be it known that 1, CHARLES P. STEIN- Mn'rz, a citizen. of the United States, residing at Sdhhect'ady county of Schenectady, State of New Yor have invented certain new and useful Improvements in Arc-Lamp Electrodes, of which the following is a specification.

The object of my present invention is to improve the operation and increase the ciliciency' of arc lamps by improving the light-' giving qualities of the electrodes employed. As is well known in an arc lamp employing the ordinary form of electrodes made out of carbon,the bulk of the light emitted is due to the incandescence of one or both of the electrodes rather than to the luminosity -of the arc itself. I have found however that if titanium, either in the pure state or in the form of achemical compound such as titamum carbid or mod, is introduced into an ordinary carbon electrode employed in conjunction with a similar electrode, or with an ordinar carbon electrode to which no such matter as been added, a luminous arc'yieldin intense white light may be obtained. n direct current lamps I ordinarily ema ploy the'electrode containing carbon and titanium as thepositive electrode in conjunction with a negative electrode composed of carbon.- The titanium is preferably employed in the positive electrode because the lig or temperature of the positive causes a.

more ready vaporization of the titanium into the are. In alternating current lamps the presence of titanium in but one of the electrodes is sutlicient, it not bein necessary that both electrodes should contain titanium.

In the construction of these electrodes, carbon and the titanium'may be mixed together to form a powdered mass'from which electrodes may be formed in the manner employed in making ordinary carbon electrodes. The ratio of thetitanium to the carbon in the electrode may vary somewhat.

Specification of Letters Patent.

Applieationfiled December 10, 1903. Serial No. 184,669.

trode should be sutlicient to insure the Patented Dec.30, 1-913.-

. according tothe dimensions of the electrodef current employed, or other conditions 0 use. The amount of titanium in the elecresence in the arc of a suiiicient supply 0 vapors containing titanium to properly color it and add to its luminosity. Titanium should not be resent in such amount however that it Wlfi not be consumed by the are as rapidly as the carbon. The presence of titanium in excess of this amount results in the accumulation of titanium at the electrode tip which is or may be objectionable. r

When on account of the low current employed, or for" other reasons, the electrode is but slowly consumed the percenta e of titanium or titanium compound shou d be considerably higher than where the electrode,

is comparatively rapidly consumed. In

eneral however the percentage of titanium 1n the electrode will be small, in'some cases taining the constituents above specified, thevaporized carbon forms'the principal agent for carryin the current between the ele'e-,

trodes. Sac an are therefore possessesthe characteristic features of. the carbon are, including inherent stability. At the same time the presence of the titanium vaporized into the arc gives it a very desirable white color and materially increases its luminosity. i What I claim as new, and desire to secure by Letters Patent of'the United States, is,-

An arc light electrode yielding a luminous white arc, composed of carbon associated with titanium carbid or its described equivalents. 1

In witness whereof I have hereunto set my hand this 7th day of December, 1903.

' CHARLES P. STEINMETZ. Witnesses: I

BENJAMIN B. HULL, BURTON C. ANTHONY. 

